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  <title>返回值</title>

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</div><hr /><div id="functions.returning-values" class="sect1">
   <h2 class="title">返回值</h2>

   <p class="para">
    值通过使用可选的返回语句返回。可以返回包括数组和对象的任意类型。返回语句会立即中止函数的运行，并且将控制权交回调用该函数的代码行。更多信息见
    <span class="function"><a href="function.return.html" class="function">return</a></span>。
   </p>
   <blockquote class="note"><p><strong class="note">Note</strong>: 
    <p class="para">
     如果省略了 <span class="function"><a href="function.return.html" class="function">return</a></span>，则返回值为 <strong><code>NULL</code></strong>。
    </p>
   </p></blockquote>
   <p class="para">
    <div class="example" id="example-157">
     <p><strong>Example #1 <span class="function"><a href="function.return.html" class="function">return</a></span> 的使用</strong></p>
     <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #007700">function&nbsp;</span><span style="color: #0000BB">square</span><span style="color: #007700">(</span><span style="color: #0000BB">$num</span><span style="color: #007700">)<br />{<br />&nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;</span><span style="color: #0000BB">$num&nbsp;</span><span style="color: #007700">*&nbsp;</span><span style="color: #0000BB">$num</span><span style="color: #007700">;<br />}<br />echo&nbsp;</span><span style="color: #0000BB">square</span><span style="color: #007700">(</span><span style="color: #0000BB">4</span><span style="color: #007700">);&nbsp;&nbsp;&nbsp;</span><span style="color: #FF8000">//&nbsp;outputs&nbsp;'16'.<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
     </div>

     </div>
   </p>

   <p class="para">
    函数不能返回多个值，但可以通过返回一个数组来得到类似的效果。
   </p>
   <p class="para">
    <div class="example" id="example-158">
     <p><strong>Example #2 返回一个数组以得到多个返回值</strong></p>
     <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #007700">function&nbsp;</span><span style="color: #0000BB">small_numbers</span><span style="color: #007700">()<br />{<br />&nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;array&nbsp;(</span><span style="color: #0000BB">0</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">1</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">2</span><span style="color: #007700">);<br />}<br />list&nbsp;(</span><span style="color: #0000BB">$zero</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$one</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$two</span><span style="color: #007700">)&nbsp;=&nbsp;</span><span style="color: #0000BB">small_numbers</span><span style="color: #007700">();<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
     </div>

     </div>
   </p>
   <p class="para">
    从函数返回一个引用，必须在函数声明和指派返回值给一个变量时都使用引用运算符 &amp;：
   </p>
   <p class="para">
    <div class="example" id="example-159">
     <p><strong>Example #3 从函数返回一个引用</strong></p>
     <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #007700">function&nbsp;&amp;</span><span style="color: #0000BB">returns_reference</span><span style="color: #007700">()<br />{<br />&nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;</span><span style="color: #0000BB">$someref</span><span style="color: #007700">;<br />}<br /><br /></span><span style="color: #0000BB">$newref&nbsp;</span><span style="color: #007700">=&amp;&nbsp;</span><span style="color: #0000BB">returns_reference</span><span style="color: #007700">();<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
     </div>

     </div>
   </p>
   <p class="simpara">
    有关引用的更多信息, 请查看<a href="language.references.html" class="link">引用的解释</a>。
   </p>
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